1. Field of the Invention
The present invention relates generally to concentricity gauges and more particularly, to an improved precision concentricity gauge which is entirely self-contained and portable and which provides a convenient means for measuring the deviation from concentricity of a bore, recess or periphery of a round part wherein deviation from concentricity can be easily read from the graduated dial of a dial indicator.
2. Prior Art
The general concept of providing a gauge-like device for measuring the concentricity of a workpiece is old in the art. However, prior art devices which are capable of providing a precise indication of eccentricity of a part or workpiece suffer the disadvantage of being relatively complex in structure and therefore, costly to manufacture and expensive to the purchaser. Furthermore, such costly devices are typically required in the quality control and inspection departments of manufacturing companies. However, because of the high cost, the manufacturer is discouraged from purchasing a sufficient quantity of such gauges. The inadequate number of such expensive gauges in a typical inspection or quality control department creates a bottleneck in the production line thereby indirectly further increasing the costs of products that gauges of that type are used to inspect. Furthermore, irrespective of the costs of such prior art devices, the complexity of their use also adds to the delay incurred in inspection departments and quality control departments for assessing the concentricity of such parts. Consequently, there has been a long-felt need for a concentricity gauge which is simple in structure, inexpensive to produce and simple and expedient to utilize by permitting rapid placement of the workpiece in the gauge for measurement.
Typical prior art concentricity gauges include those disclosed in the following U.S. Pat. Nos.: 2,831,258 (Eisele); 4,222,173 (Hall; 4,414,748 (Gauler et al).
Other less relevant prior art consists of the following U.S. Pat. Nos.: 2,806,294 (Cargill); 3,125,811 (Pierce et al); 3,564,721 (Wilson); 3,826,011 (D'Aniello); 4,080,741 (Siddal et al); 4,517,744 (Consales et al); 4,531,294 (Lenz).
U.S. Pat. No. 2,831,258 to Eisele is directed to what is termed a precision eccentricity gauge which provides for a gauge member mounted to a gauge holder which is movable in an axial direction. This prior art system includes a probe which is insertable into the bore of a workpiece. However, this reference typifies the complexity and expense of prior art gauges of the type herein disclosed. By way of further example, U.S. Pat. No. 4,414,748 to Gauler et al is directed to a ball mounting fixture for a roundness gauge. A stylus is offset radially from the axis of a spindle approximately the distance of the radius of the ball. The stylus travels in a substantially horizontal orbit around the ball as opposed to linear displacement. A vertical chuck assembly supports the ball in a stationary position when the measurements are taken and rotates the ball about a vertical axis, U.S. Pat. No. 4,222,173 to Hall is directed to a shaft and bore misalignment measuring tool showing a dial member coupled to a probe member for measuring the concentricity of a bore of a workpiece. Unfortunately, none of the aforementioned prior art patents nor any other prior art known to the applicant, satisfies the aforementioned long-felt need for a simple, portable, self-contained, low cost concentricity gauge which is reliable and precise and which permits convenient placement and replacement of the parts to be measured.